First-Principles Study of Thermo-Physical Properties of Pu-Containing Gd₂Zr₂O₇

Pengcheng Li; Fengai Zhao; Haiyan Xiao; Haibin Zhang; Hengfeng Gong; Sa Zhang; Zijiang Liu; Xiaotao Zu

doi:10.3390/nano9020196

First-Principles Study of Thermo-Physical Properties of Pu-Containing Gd₂Zr₂O₇

Nanomaterials (Basel). 2019 Feb 3;9(2):196. doi: 10.3390/nano9020196.

Authors

Pengcheng Li¹, Fengai Zhao², Haiyan Xiao³, Haibin Zhang⁴, Hengfeng Gong⁵, Sa Zhang⁶, Zijiang Liu⁷, Xiaotao Zu^{8

9}

Affiliations

¹ School of Physics, University of Electronic Science and Technology of China, Chengdu 610054, China. pengchengli257335@gmail.com.
² Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu 610054, China. fengaizh0506@163.com.
³ School of Physics, University of Electronic Science and Technology of China, Chengdu 610054, China. hyxiao@uestc.edu.cn.
⁴ Institute of Nuclear Physics and Chemistry, Chinese Academy of Engineering Physics, Mianyang 621900, China. hbzhang@imr.ac.cn.
⁵ Department of ATF R&D, China Nuclear Power Technology Research Institute Co., Ltd., Shenzhen 518000, China. gonghengfeng@cgnpc.com.cn.
⁶ School of Physics, University of Electronic Science and Technology of China, Chengdu 610054, China. 15136231837@163.com.
⁷ Department of Physics, Lanzhou City University, Lanzhou 730070, China. lzjcaep@126.com.
⁸ School of Physics, University of Electronic Science and Technology of China, Chengdu 610054, China. xtzu@uestc.edu.cn.
⁹ Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu 610054, China. xtzu@uestc.edu.cn.

Abstract

A density functional theory plus Hubbard U method is used to investigate how the incorporation of Pu waste into Gd₂Zr₂O₇ pyrochlore influences its thermo-physical properties. It is found that immobilization of Pu at Gd-site of Gd₂Zr₂O₇ has minor effects on the mechanical and thermal properties, whereas substitution of Pu for Zr-site results in remarkable influences on the structural parameters, elastic moduli, elastic isotropy, Debye temperature and electronic structure. The discrepancy in thermo-physical properties between Gd_2-yPu_yZr₂O₇ and Gd₂Zr_2-yPu_yO₇ may be a result of their different structural and electronic structures. This study provides a direct insight into the thermo-physical properties of Pu-containing Gd₂Zr₂O₇, which will be important for further investigation of nuclear waste immobilization by pyrochlores.

Keywords: DFT+U; Gd2Zr2O7; mechanical properties; nuclear waste.

Abstract

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